I realize that many of us veteran reconstructers will not need a tutorial for this, but when I was just starting out last year, I would have killed for one of these! I had to gather snippets of technique info from dozens of sources. But I've refined my method from these, and since I was super pleased with the tee I made yesterday, I wanted to do another, and I took photos every step along the way!

Disclaimer: This is certainly not the only way to do things, just my way, the way I have found gives me the best results with the least likelihood of mistakes. If you have another method for your tees, feel free to cherry-pick from my advice instead of going whole hog!

Also, I apologize for the spotty bathroom mirror, I didn't notice it until I was editing the images, and of course by then it was far too late!

You will need a t-shirt or other knit-fabric shirt that is too large for you, and all your general sewing goodies--scissors, matching thread, seam ripper, a suitable marking pen/chalk for your fabric, etc. I recommend a walking foot for your sewing machine, it makes working with knit fabric much, much easier. Also, it's handy to have a well-fitting shirt to base your new shirt on, but it's not absolutely necessary. And, for the optional contrast bands, you'll need knit fabric scraps of a similar weight to the shirt you're altering, in a different color. A suitably-sized dress form would be a godsend if you have one; I don't, sadly. I tried to make one and it went very, very badly.

Something I totally forgot to mention the first time: If you're using a guide shirt, try to use one that has about the same elasticity as the shirt you're altering. Using a firm guide on a stretchy shirt will make your new shirt too big (easy enough to fix in the early stages); using a stretchy guide on a firm shirt will definitely leave your new shirt too small, which is not so easy to fix--ask me how I know this! If it can't be helped that the shirts are different, think ahead and draw your lines farther out the first time, echoing the shape of the shirt instead of tracing it directly.

Here you see my original tee; a little loose in the bust, a lot in the waist, too long, too high a neck. I had to take my glasses off every time it went over my head in either direction!

Cut off the sleeves, including the seam, and set aside for later. Lay the shirt out flat, wrong side out.

If you like the length of the shirt as it is, you can keep the original hem; in that case, I find it helpful to pin the edges together to keep them aligned during marking and sewing. If you're going to shorten the shirt, this isn't strictly necessary.

Lay your guide shirt down on top, matching up the shoulder seams. Fold back the sleeve as best you can to get the shape of the armhole. (If you don't have a guide shirt, put the shirt you're altering on inside-out after you've cut off the sleeves and decide how much you want to take in the sides; mark it with pins, and proceed.)

Draw around the outside of your guide shirt (or connect your pins) with your marking device (a chalk in my case). I followed the side and armhole exactly, but left myself several extra inches at the bottom to form a hem later.

Sew down the marked lines using a narrow zigzag stitch; a straight stitch won't stretch with the fabric. If your machine has a specific stretch stitch, try it out on a scrap to see if you like it; I don't like mine, so I stick with the zigzag.

Try it on. Inside-out is fine, just hold the flaps of extra fabric out of the way. You can see here that mine is quite tight; tighter than I like it, in fact. Err on the side of looseness whenever possible; it's easier to sew a new seam to make it smaller than to rip out the one you just put in to make it bigger. Which is what I had to do.

Here is the improved version, that doesn't stretch unduly across the bust.

When you are satisfied with the fit, and only then, you can cut off the excess fabric, leaving yourself a small seam allowance.

Next, cut away the armholes just outside of your marked lines. (If you don't have marked armholes because you didn't use a shirt, decide on how wide you'd like your shoulders while you have the shirt on, and mark the width with a pin. Draw a reasonable armhole shape from there to the side seam.)

Take your sleeves and cut away the shoulder seams, then line them up like so to compare. My armholes got smaller, so now the sleeves are slightly too big.

Slip the sleeve under the armhole like so, adjusting until you like the position, and both the shoulder and the underarm line up neatly. This angled position is a common cap-sleeve type...

...but personally, I prefer the straight-shoulder alignment. It really bothers me when lifting my arms too high makes my clothing ride up! Either way will work just fine, and there's no difference in the actually construction method, so go with whatever you like best. Once you decide, mark the edge of the armhole onto the sleeve to get the shape...

...like so. You can see I'm not losing very much fabric; the sleeve won't get much shorter. If you do want shorter sleeves, just move the sleeve farther in before you mark the armhole.

Now, an optional step. If you want to add contrast bands to your sleeves, do the following: Cut your sleeves open and remove the underarm seam entirely. Cut a strip of fabric at least as long as the sleeve hem, and twice as wide as the (sleeve hem + the width of the contrast band that you want to show beneath it). Fold this strip in half, wrong sides together.

Lay your opened sleeve on top and pin together. (You can see my strip is a bit wider than necessary, but I had precut strips from an earlier failed project, so I just used those.)

Sew the band to the sleeve, stitching between the two lines of the original hem. Cut off any excess fabric from the back, being careful not to cut into the seam or the sleeve.

Sew a new underarm seam and turn right-side out. Repeat with the other sleeve.

Skipped the optional step? Start again here.

Setting in the sleeve. This is by far the thing I had the most trouble with when I started, and the least help available, so I'll try to make this as clear as I can!

Start by marking the top fold of the sleeve with a pin at the raw edge. With your sleeve right-side out, and your shirt inside-out, drop the sleeve into the armhole, lining up the underarm seam with the body side seam, and the pin at the top with the shoulder seam.

Pin securely in place--I use two closely-spaced pins on either side of the seams, like so.

Now this is the part that's hard to demonstrate with pictures, at least without a third hand! Match the edges of the sleeve and armhole together halfway in between your pins, and pin those on both sides, dividing it into quarters. Do it again in those four sections. You'll probably notice some serious gaps in between those pins, where the body fabric sags away from the sleeve. That's okay, I promise. Now, take each section in your hands, fingers on pins, and stretch it slightly, until the two edges line up properly--it will make more sense when you do it. Stick another pin in the center of that, while stretched, and continue like that all the way around. This is to distribute the fullness of the armhole evenly--otherwise you might get unsightly puckers in your seam.

When it's all done, it will look something like this. Carefully, (carefully!) sew the shoulder seam all the way around, starting near the underarm seam. While you sew, stretch the fabric lightly before it goes under the needle; don't use enough resistance to make your machine unhappy, just enough to make the two layers of fabric lie smoothly together as they pass the needle.

Turn right-side out and try it on!

My sleeve is snug, but not too tight; and as you can see, I have excellent range of motion with the straight-shoulder alignment

Repeat with the other sleeve.

Now, this is the first place you might be "done" with the shirt. If you kept the original hem, or if you want to leave the bottom of your altered hem raw; and if you don't want to alter the neck. Pat yourself on the back and enjoy your new shirt!

Up next, the hem.

Put on your shirt inside-out and pin up the hem to the desired depth. Carefully (!) take it off and sew the hem. Trim any excess fabric away from the inside, again, being careful not to cut into the seam or the body of the shirt.

You might be done now if you're happy with the original neck. Pat yourself on the back, again!

Optional step: altering the neckline.

Put on your shirt and decide how deep you'd like your new neckline, keeping in mind the finished opening will be a bit smaller because of the contrast band. Put a pin in the center front at the desired depth.

Take off the shirt and lay it flat. Cut down the center front from the neckline to the pin.

From the pin, cut a smooth curve in your desired shape to one shoulder seam, then cut the loose piece away from the seam. (In the picture mine is still attached, oopsie!)

Flip it over and lay it against the neck on the opposite side; cut around it.

Also, cut off the back neck binding. (You can shape the back neck too, if you like, just the same way; sometimes I do, and sometimes I don't.)

Cut a strip of your contrast fabric twice as wide as (desired depth of band + seam allowance), and long enough to go around the whole neck. If I'm working from scraps of old shirts, I usually have to piece two strips together, and that's fine. Fold your long strip in half, wrong sides together.

Begin pinning the strip to the right side of the neck edge, starting about an inch before either shoulder seam.

Pin all the way around. As you go, stretch the strip before you pin it in place, especially at the curves; this will help the neck binding lie flat. Be warned, though; if your strip is very wide, or your fabric not very stretchy, it might not lie entirely flat--you'll see the difference between the two at the end. When you get all the way around, cut off the excess, leaving about an inch of overlap.

Open the folded strip and match the two ends right sides together. (You may need to remove the first pin on either side of the join to get enough slack.) Sew together, refold, and check against the neck edge; if it's too loose, sew again a bit farther in, too tight, rip the seam out and try again a bit closer to the ends.

Once you're happy with it, refold and pin in place.

Sew around, stretching lightly as you did with the sleeves. Try it on!

If you're happy with it, top stitch along the edge, making sure to sew through the seam allowance; this will stop the neck band from rolling to the outside and exposing the seam.

Voila! The finished shirt! You can see that here my neck band does not, in fact, lie entirely flat: I expected this, as my contrast fabric was firm, and I made the band wide. I don't mind that it stands up a little, I actually think it looks rather cute.

Here, on the other hand, is the tee I made yesterday; it has a deeper scoop neck instead of a rounded v-neck, and the contrast fabric was quite elastic, so I was able to stretch it much more while pinning.

So for binding curves, remember: narrower bands and more elastic fabrics will lie flatter than wider bands and firmer fabrics. Use this to your advantage to get the style you want!

Still with me? Now you're really done! I promise!

Any questions, feel free to ask, and if you make one, be sure to show it off, I'd love to see it!

Thanks for posting this -- the step-by-steps and photos are a great help. Most of the t-shirt-fitting tutorials I've seen use a similar method, but tend lack in-depth coverage of the process. Being short and curvy, it's really hard to get an even moderately well-fitting tee, and though intrigued to give it a go, I haven't been confident enough of the information I found to try a remodel. Now I am, and will definitely be referring to your instructions when I finally get around to it (though I think I'll first work with a shirt I don't care so much about...).

You are my new favorite person. I have so many cool shirts from museums, plays, etc but they're always the same boring ol' unisex cut. I've always been terrified to cut into them, though, because if I screw up then that's a t-shirt lost! This looks doable.